http://english.aljazeera.net/news/eu...223290617.html
Air France experts dismiss human error report
Investigators analysing data from flight 447 say cause of crash still unknown, after paper clears Airbus of blame.
French accident investigators have criticised a newspaper for reporting that flight recorders from the fatal 2009 Air France crash showed human error was to blame.

Le Figaro, a French daily, said one of the so-called black boxes had already yielded enough information to conclude that the crash was not caused by a fault in the Airbus aircraft, but did not explain how the conclusion was reached.

An Air France jet that crashed into the Atlantic Ocean two years ago stalled three times before plunging into the sea, killing all 228 people on board, information from the plane's flight recorders shows.

French investigators said on Friday that data from the devices, known as black boxes, revealed the final minutes of the air disaster, with two co-pilots struggling to regain control of the Airbus jet.

The emergency began with a stall warning two and a half hours into flight 447 between Rio de Janeiro and Paris on June 1 2009.

The captain was on a routine break at the time and was summoned back to the cockpit by the second and third in command, but did not retake the controls.

The co-pilots wrestled with the plane's controls for three and a half minutes as it descended rapidly, falling 3,350 metres per minute, rolling from left to right and finally plunging into the Atlantic.

"There was an inconsistency between the speeds displayed on the left side and the integrated standby instrument system (ISIS), the French Bureau of Inquiry and Analysis (BEA), said.

"This lasted for less than one minute".

However the investigators said it is still too early to give the causes of the crash, and a full report is expected to be released this summer.

Airbus said the information released on Friday was consistent with the BEA's preliminary and interim reports and "constitutes a significant step towards the identification of the complete chain of events" that led to the crash.

According to the chronology provided by the BEA, the two co-pilots who were flying the plane decided at two hours and eight minutes into the flight to turn slightly to the left to avoid a zone of turbulence.

Two minutes later the autopilot disengaged, the instruments began showing "a sharp fall" in airspeed and the engine stall warning began to sound.

"So, we've lost the speeds," it quoted the second of the two co-pilots as saying.

After the captain returned, "all of the recorded speeds became invalid and the stall warning stopped," said the BAE report.

The last data on the recorder showed that the plane's nose was up at a sharp angle as it plunged into the ocean.

The BAE report said "the composition of the crew was in accordance with the operator's procedures."

The captain would normally take a rest during the flight and leave the two co-pilots at the controls.

There are. One is a FDR (Flight Data Recorder aka the "black box") that records all the control surface inputs (such as rudder and aileron) and other data such as airspeed, altitude, G-forces, etc...
The other box is a CVR (Cockpit Voice Recorder) which does what it says on the tin
Both can withstand upto 310mph impact velocity and will survive as deep as 20,000ft below the surface. They stop emitting a tracking beacon after 30 days, which is why after 30 days the probability of finding them drastically reduces, but not entirely impossible.

There was an unofficial Air Crash Investigation documentary last year, where they took into account the weather condition's (the aircraft was struck by lightening, which is what caused the Airbus to send a warning message to ATC as a default failsafe built in by the manufacturer) and they came to the conclusion that super chilled water had built up in the pitot tubes (the tubes that air rushed into and is used to generate an airspeed reading) eventually leading to a loss of altitude because the pilots assumed they were losing speed. Piloting 101, to gain speed you lower the nose of the aircraft or increase throttle inputs. They lowered the nose, not realising the air turbulence had already cost them altitude. Eventually they crashed into the water.
Add to this the fact the flight crew were new to the aircraft with I think less than 100 hours combined between the captain and the first officer, so their inexperience on the airbus flight deck played a part as well.

Apparently the plane was at a 35 degree angle of attack the majority of the drop from 38,000 feet. They were in a stall, and the computer was trying to give stall warnings, but somehow it wasn't getting to the pilots.

Quote:

Originally Posted by ebolamonkey3

So not human error, but not Airbus' fault either?

Based on what I read, the weather was pretty terrible. A "perfect-storm" series of events very well could have caused the crash.

However, I'm surprised to see people speculate that Airbus is completely free of fault in this accident, considering they have had a history of instrumentation problems.

Plus, everything I read points to the fact that the plane was giving the pilots absolutely no idea of what was occurring.Edited by SectorNine50 - 5/27/11 at 4:53pm

According to the BEA the plane stalled early in the emergency and stayed in a stall condition all the way until impact. What is very disturbing is that they state that "the inputs made by the PF were mainly nose-up". I assume that the pilots got very conflicting message from the plane and didnt recognize the stall condition until it was too late.

So likely stalled, but did not tell the crew it was in stall state... wouldn't that kinda put blame on the manufacture of the plane? and I read else where that the air speed tubes are known for getting clogged on some types of planes - and there has been a fix issued for it. also combine this with a particular model of rolls royce engine that is known to have issues...